I.
The subject invention is in the field of selective irreversible inhibitors of the enzyme monoamine oxidase (hereinafter MAO) and provides the [R](+)enantiomer of N-propargyl-1-aminoindan (also referred to herein as PAI) which is a selective irreversible inhibitor of the B-form of monoamine oxidase enzyme (hereinafter MAO-B). The subject invention also provides pharmaceutical compositions containing [R](+)PAI which are particularly useful for the treatment of Parkinson's disease, a memory disorder, dementia, depression, hyperactive syndrome, an affective illness, a neurodegenerative disease, a neurotoxic injury, brain ischemia, a head trauma injury, a spinal trauma injury, schizophrenia, an attention deficit disorder, multiple sclerosis, and withdrawal symptoms.